Carbon black can be produced in various ways. One particularly successful way is to pyrolytically decompose hydrocarbon feedstocks that are gaseous or liquid under normal pressure and temperature conditions in a furnace. The heat for this thermal decomposition is usually generated by hot combustion gases, e.g., by the combustion products of natural gas and air. One furnace that has proven to be very efficient is the socalled 0-type carbon black reactor. This reactor has a precombustion section of greater diameter than the diameter of the reaction section, and is in axial alignment and in open communication with the reaction section. Whereas such a reactor has proven to be very successful in producing high quality carbon black, the specifications carbon black has to meet become more and more severe and more and more difficult to comply with. Particularly, it would be advantageous to have an 0-type carbon black reactor available that can produce carbon black with high tint or with narrow particle size distribution without having to sacrifice other valuable properties of the carbon black such as the surface area.